1 /* 2 * Copyright (C) ST-Ericsson AB 2010 3 * Author: Sjur Brendeland/sjur.brandeland@stericsson.com 4 * License terms: GNU General Public License (GPL) version 2 5 */ 6 7 #include <linux/stddef.h> 8 #include <linux/spinlock.h> 9 #include <linux/slab.h> 10 #include <net/caif/caif_layer.h> 11 #include <net/caif/cfsrvl.h> 12 #include <net/caif/cfpkt.h> 13 14 #define container_obj(layr) ((struct cfsrvl *) layr) 15 16 #define DGM_CMD_BIT 0x80 17 #define DGM_FLOW_OFF 0x81 18 #define DGM_FLOW_ON 0x80 19 #define DGM_CTRL_PKT_SIZE 1 20 #define DGM_MTU 1500 21 22 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt); 23 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt); 24 25 struct cflayer *cfdgml_create(u8 channel_id, struct dev_info *dev_info) 26 { 27 struct cfsrvl *dgm = kmalloc(sizeof(struct cfsrvl), GFP_ATOMIC); 28 if (!dgm) { 29 pr_warning("CAIF: %s(): Out of memory\n", __func__); 30 return NULL; 31 } 32 caif_assert(offsetof(struct cfsrvl, layer) == 0); 33 memset(dgm, 0, sizeof(struct cfsrvl)); 34 cfsrvl_init(dgm, channel_id, dev_info, true); 35 dgm->layer.receive = cfdgml_receive; 36 dgm->layer.transmit = cfdgml_transmit; 37 snprintf(dgm->layer.name, CAIF_LAYER_NAME_SZ - 1, "dgm%d", channel_id); 38 dgm->layer.name[CAIF_LAYER_NAME_SZ - 1] = '\0'; 39 return &dgm->layer; 40 } 41 42 static int cfdgml_receive(struct cflayer *layr, struct cfpkt *pkt) 43 { 44 u8 cmd = -1; 45 u8 dgmhdr[3]; 46 int ret; 47 caif_assert(layr->up != NULL); 48 caif_assert(layr->receive != NULL); 49 caif_assert(layr->ctrlcmd != NULL); 50 51 if (cfpkt_extr_head(pkt, &cmd, 1) < 0) { 52 pr_err("CAIF: %s(): Packet is erroneous!\n", __func__); 53 cfpkt_destroy(pkt); 54 return -EPROTO; 55 } 56 57 if ((cmd & DGM_CMD_BIT) == 0) { 58 if (cfpkt_extr_head(pkt, &dgmhdr, 3) < 0) { 59 pr_err("CAIF: %s(): Packet is erroneous!\n", __func__); 60 cfpkt_destroy(pkt); 61 return -EPROTO; 62 } 63 ret = layr->up->receive(layr->up, pkt); 64 return ret; 65 } 66 67 switch (cmd) { 68 case DGM_FLOW_OFF: /* FLOW OFF */ 69 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_OFF_IND, 0); 70 cfpkt_destroy(pkt); 71 return 0; 72 case DGM_FLOW_ON: /* FLOW ON */ 73 layr->ctrlcmd(layr, CAIF_CTRLCMD_FLOW_ON_IND, 0); 74 cfpkt_destroy(pkt); 75 return 0; 76 default: 77 cfpkt_destroy(pkt); 78 pr_info("CAIF: %s(): Unknown datagram control %d (0x%x)\n", 79 __func__, cmd, cmd); 80 return -EPROTO; 81 } 82 } 83 84 static int cfdgml_transmit(struct cflayer *layr, struct cfpkt *pkt) 85 { 86 u32 zero = 0; 87 struct caif_payload_info *info; 88 struct cfsrvl *service = container_obj(layr); 89 int ret; 90 if (!cfsrvl_ready(service, &ret)) 91 return ret; 92 93 /* STE Modem cannot handle more than 1500 bytes datagrams */ 94 if (cfpkt_getlen(pkt) > DGM_MTU) 95 return -EMSGSIZE; 96 97 cfpkt_add_head(pkt, &zero, 4); 98 99 /* Add info for MUX-layer to route the packet out. */ 100 info = cfpkt_info(pkt); 101 info->channel_id = service->layer.id; 102 /* To optimize alignment, we add up the size of CAIF header 103 * before payload. 104 */ 105 info->hdr_len = 4; 106 info->dev_info = &service->dev_info; 107 ret = layr->dn->transmit(layr->dn, pkt); 108 if (ret < 0) { 109 u32 tmp32; 110 cfpkt_extr_head(pkt, &tmp32, 4); 111 } 112 return ret; 113 } 114